To markup any arbitrary string of text (not necessarily a page title) as a link, use a "vertical bar" or "pipe" character, like this: [[Help:Categories|category links]] results in the link category links.

If the page title you are linking to is that of the page you are editing, the result is not a hyperlink at all but simply bold text (for example, on this page the markup [[Help:Links/es]] gives the result Help:Links/es). If you're trying to create a wikilink to the current page, you probably want to link to a specific section or to an anchor within the page; see the examples below.

Rendered block-level and inline, respectively.
Doing this would allow for [[#Unique anchor name 1]] on the same page or [[Help:Links/es#Unique anchor name 1]] on a different page.
Omit the "optional text" for an invisible anchor.

Setting an anchor in a section heading

==<span id="Alternate Section Title"></span>Section heading==

Note the placement.
This must be a "span" tag, not a "div".
(Such anchors allow sections to be retitled without breaking incoming links.)

Revision numbers can be found in each page's edit history.
(It is very common to see links to specific revisions implemented as external links because it's easy to cut-and-paste an entire URL to form an external link.)

The link will be HTTP or HTTPS depending on the protocol of the page currently being viewed (which could be different for different users).
This is only supported inside of square brackets [ ].
Using "//en.wikipedia.org" by itself does not result in a link.

Enlaces interwikis

Interwiki links are internal-style links to other websites (which do not have to be wikis, despite the name). For example, you can link to the article http://en.wikipedia.org/wiki/Sunflower by typing [[wikipedia:Sunflower]] or, on this wiki, the shorter [[w:Sunflower]]. Both will result in a link wikipedia:Sunflower. This works because by default MediaWiki configures wikipedia: as an "interwiki prefix" that turns into http://en.wikipedia.org/wiki/ when used inside [[ ]]. (It may not work if the admin of your wiki has changed the setting.) Unlike internal links, interwiki links do not use page existence detection, so an interwiki link will appear blue even if the page does not exist on the remote wiki.

Similar to internal page links, you can create piped links, with alternate link label, e.g. [[wikipedia:Sunflower|big yellow flower]] is the link big yellow flower and [[wikipedia:Sunflower|]] is the link Sunflower.

Basically, interwiki links are abbreviations for commonly-used longer external links. A very similar link could be created as [http://en.wikipedia.org/wiki/Sunflower big yellow flower].

Enlaces interidiomas

If your wiki has other language versions, you may find “interlanguage links” in the sidebar, just below toolbox in a section titled “en otros idiomas.”

In wiki markup an interlanguage link looks very much like an interwiki link, but behaves similarly to a category link in that it is rendered in a special way. While category links appear in a special list at the bottom of the page (usually), interlanguage links appear in a special list in the sidebar of the page (or elsewhere, depending on the wiki's configuration and the skin used).

The purpose of interlanguage links is to link pages on the same topics in different languages. To create an interlanguage link, type [[language prefix:page name]] anywhere in the page (preferably at the bottom, like category links); the language prefix is the prefix specified at your wiki for the other language version (typically the ISO 639-1 language code).
The interlanguage link is unilateral, it does not point back from that page in the other language.
For that purpose, an equivalent back-link needs to be placed there as well.
It does not work like the "Edit links" in the languages section of Wikipedia-language versions.
But it can be used across all name spaces, including 'User:' to point to ones other profiles in other languages.

If you want to make the interlanguage link appear at a specific place in the content of the page rather than in the sidebar, add a colon before the language prefix: